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Journées MSR de Massy, 2018 Présentation MSFR
Prof. Elsa MERLE – [email protected]
On behalf of the MSFR CNRS French Team – Michel Allibert, Sylvie Delpech, Delphine Gérardin, Lydie, Giot, Daniel Heuer, Axel Laureau, Johann Martinet, Elsa Merle
LPSC Grenoble (CNRS-IN2P3 / Grenoble INP – PHELMA / Grenoble Alpes University), Subatech Nantes and IPN Orsay (CNRS-IN2P3)
With the support of the IN2P3/CNRS institute and the PACEN and NEEDS French Interdisciplinary Programs, Grenoble Institute of Technology, and of the EVOL and SAMOFAR
Euratom Projects
Concept of Molten Salt Fast Reactor
Journées MSR de Massy, 2018 Présentation MSFR
Which constraints for a liquid fuel?• Melting temperature not too high
• High boiling temperature
• Low vapor pressure
• Transparent to neutrons
• Good thermal and hydraulic properties (fuel = coolant)
• Stability under irradiation
• Good solubility of fissile and fertile matters
• No production of radio-isotopes hardly manageable
• Solutions to reprocess/control the fuel salt
Fluoride and chloride salts fulfill all constraints
Molten Salt Reactors
Advantages of a Liquid Fuel Homogeneity of the fuel (no loading plan)
Heat is produced directly in the heat transfer fluid
Possibility to reconfigure passively the geometry of the fuel:
- One configuration optimizes the electricity production managing the criticality
- An other configuration allows a long term storage with a passive cooling system
Possibility to reprocess the fuel without stopping the reactor:
- Better management of the fission products that damage the neutronic and physicochemical characteristics
- No reactivity reserve (fertile/fissile matter adjusted during reactor operation)
Liquid-fueled reactors: why “molten salt reactors”?
2
Journées MSR de Massy, 2018 Présentation MSFR
Neutron spectrum less fast with fluoride salt = reduced irradiation
damages (both DPA and He production) with a fluoride salt
DPAMost irradiated area (central part of axial reflector – radius
20 cm/thickness 2 cm)
He productionMost irradiated area (central part of axial reflector – radius
20 cm/thickness 2 cm)
Liquid-fueled reactors: fluoride or chloride? Irradiation damages
Journées MSR de Massy, 2018 Présentation MSFR4
Element produced Problem Fluoride SaltChloride
Salt
36Cl produced via 35Cl(n,γ)36Cl and 37Cl(n,2n)36Cl
Radioactivity in waste - T1/2 =
301000y
10 moles / y (373 g/year)
3H produced via 6Li(n,) t and 6Li(n,t) Radioactivity -T1/2 = 12 years
55 moles / y (166 g/y)
Sulphur produced via 37Cl(n,)34P(-
[12.34s])34S and 35Cl(n,)32P(-[14.262
days])32S
Corrosion (located in the
grain boundaries)
10 moles / year
Oxygen produced via 19F(n,)16OCorrosion (surface of
metals)
88.6 moles/year
Tellurium produced via fissions and
extracted by the on-line bubbling
Corrosion (cf. Sulphur)
200 moles/year
200 moles/year
Liquid-fueled reactors: fluoride or chloride?Elements produced
Combination of all these considerations
‘reference MSFR’ based on a molten LiF fuel salt
Journées MSR de Massy, 2018 Présentation MSFR
Which constraints for a liquid fuel?• Melting temperature not too high
• High boiling temperature, Low vapor pressure
• Transparent to neutrons
• Good thermal and hydraulic properties (fuel = coolant)
• Stability under irradiation
• Good solubility of fissile and fertile matters
• No production of radio-isotopes hardly manageable
• Solutions to reprocess/control the fuel salt
Lithium fluorides fulfill all constraints
Neutronic cross-sections of fluorine versus neutron
economy in the fuel cycleThorium /233U Fuel Cycle
Molten Salt Reactors
F[n,n’]
Na[n,γ]
Liquid-fueled reactors: why “molten salt reactors”?
5
Choice of the fluoride salt:
• Waste considerations (production of 36Cl with chloride salt)
• Reduced irradiation damages (spectrum less fast)
Choice of the Th fuel cycle:
• Higher breeding ratio with a fluoride salt / spectrum
• Smaller production of minor actinides
Journées MSR de Massy, 2018 Présentation MSFR
Homogeneity of the fuel (no loading plan)
Heat produced directly in the heat transfer fluid
Possibility to reconfigure quickly and passively the geometry of the fuel (gravitational draining)
Possibility to reprocess the fuel without stopping the reactor
6
– Safety: negative feedback coefficients
– Sustainability: reduce irradiation damages in the core
– Deployment: good breeding of the fuel + reduced initial fissile inventory
Neutronic Optimization of MSR
(Gen4 criteria) :
Historical studies of MSR: Oak Ridge Nat. Lab. - USA
6
1964 – 1969: Molten Salt Reactor Experiment (MSRE) - 7.4 MWth – 650°CenrU enriched 30% then 233U and 239Pu
1970 - 1976: Molten Salt Breeder Reactor (MSBR) - 2500 MWth - ProjectRe-evaluation 15 years ago → highlight some problems (safety, graphite, processing)
1954 : Aircraft Reactor Experiment (ARE) – 2.5 MWth – Operated 1000h
MSR - Renewal of the concept – CNRS studies
Fluoride salt and graphite matrix – Thermal neutron spectrum
Journées MSR de Massy, 2018 Présentation MSFR
- core volume adjusted to keep the same salt volume -
r = 4 cm
r = 8.5 cm
single channel
3 different moderation ratios/spectra:
thermal fast
7
Fast spectrum
Epithermal spectrum
Thermal spectrum
Historical MSR Studies at CNRSInfluence of the neutron spectrum –Parametric studies
PhD thesis of Ludovic MATHIEU
Journées MSR de Massy, 2018 Présentation MSFR
Thermal spectrum configurations
- low 233U initial inventory- quite long graphite life-span- iso-breeder- positive feedback coefficient
Epithermal spectrum configurations
- quite low 233U initial inventory- very short graphite life-span
- quite negative feedback coefficient- iso-breeder
Fast spectrum configurations (no moderator)- very negative feedback coefficients
- very good breeding ratio
- no problem of graphite life-span
- medium 233U initial inventory
Historical MSR Studies at CNRS
8
The Molten Salt Fast Reactor -
MSFR
Journées MSR de Massy, 2018 Présentation MSFR
Reactor Design and Fissile Inventory Optimization = Specific Power Optimization
2 parameters:
3 limiting factors:
• The produced power• The fuel salt volume and the core geometry
Liquid fuel and no solid matter inside the core possibility to reach specific power much higher than in a solid fuel
Reference MSFR configuration with 18 m3 and 330 W/cm3 corresponding to an initial fissile inventory of 3.5 tons per GWe
• The capacities of the heat exchangers in terms of heat extraction and the associated pressure drops (pumps) large fuel salt volume and small specific power
• The neutronic irradiation damages to the structural materials (in Ni-Cr-W alloy) which modify their physicochemical properties. Three effects: displacements per atom, production of Helium gas, transmutation of Tungsten in Osmium large fuel salt volume and small specific power
• The neutronic characteristics of the reactor in terms of burning efficiencies small fuel salt volume and large specific power and of deployment capacities, i.e. breeding ratio (= 233U production) versus fissile inventory optimum near 15-20 m3 and 300-400 W/cm3
MSFR: Design and Fissile Inventory Optimization
9
Voir présentation de M. Allibert
Journées MSR de Massy, 2018 Présentation MSFR
Homogeneity of the fuel (no loading plan)
Heat produced directly in the heat transfer fluid
Possibility to reconfigure quickly and passively the geometry of the fuel (gravitational draining)
Possibility to reprocess the fuel without stopping the reactor:
Concept of Molten Salt Fast Reactor (MSFR)
– Safety: negative feedback coefficients
– Sustainability: reduce irradiation damages in the core
– Deployment: good breeding of the fuel + reduced initial fissile inventory
Neutronic Optimization of MSR
(Gen4 criteria) :
2008: Definition of an innovative MSR concept based on a fast neutron spectrum, and called MSFR (Molten Salt Fast Reactor) by the GIF Policy Group
All feedback thermal coefficients negative
No solid material in the high flux area: reduction of the waste production of irradiated structural elements and less in core maintenance operations
Good breeding of the fissile matter thanks to the fast neutron spectrum
Actinides burning improved thanks to the fast neutron spectrum
10
Journées MSR de Massy, 2018 Présentation MSFR
Three circuits:Fuel salt circuit
General characteristics:• Fuel = coolant• Liquid circulating fuel• Thermal yield: 45%• Fast neutron spectrum• Thorium fuel cycle
Description of the Molten Salt Fast Reactor (MSFR) system
Journées MSR de Massy, 2018 Présentation MSFR
General characteristics:• Liquid circulating fuel• Fuel = coolant• Thermal yield: 45%• Fast neutron spectrum• Thorium fuel cycle
Description of the Molten Salt Fast Reactor (MSFR) system
M. Allibert, M. Aufiero, M. Brovchenko, S. Delpech, V. Ghetta, D. Heuer, A. Laureau, E. Merle-Lucotte, “Chapter 7 - MoltenSalt Fast Reactors”, Handbook of Generation IV Nuclear Reactors, Woodhead Publishing Series in Energy (2015)
Three circuits:Fuel salt circuitIntermediate circuitThermal conversion circuit
+ Draining / storage tanks+ Processing units
Journées MSR de Massy, 2018 Présentation MSFR13
European Project “EVOL” Evaluation and Viability Of Liquid fuel
fast reactor - FP7 (2011-2013): Euratom/Rosatom cooperation
Objective : to propose a design of MSFR by end of 2013 given the best
system configuration issued from physical, chemical and material studies
WP2: Design and Safety
WP3: Fuel Salt Chemistry and Reprocessing
WP4: Structural Materials
C
Examples of outputs of the project:
- Optimized toroidal shape of the core
- Proposal for an optimized initial fuel salt composition
- Neutronic benchmark (comparison tools/ nuclear databases)
- First developments of a safety assessment method for MSR
- Recommendations for the choice of the core structural materials
12 European Partners: France (CNRS: Coordinator, Grenoble INP , INOPRO,
Aubert&Duval), Netherlands (Technical Univ Delft), Germany (ITU, KIT-G, HZDR),
Italy (Politecnico di Torino), UK (Oxford), Hungary (Tech Univ Budapest)
+ 2 observers since 2012: Politecnico di Milano and Paul Scherrer Institute
+ Coupled to the MARS (Minor Actinides Recycling in Molten
Salt) project of ROSATOM (2011-2013)Partners: RIAR (Dimitrovgrad), KI (Moscow), VNIITF (Snezinsk), IHTE
(Ekateriburg), VNIKHT (Moscow) et MUCATEX (Moscow)
MSFR and the European project EVOL
Journées MSR de Massy, 2018 Présentation MSFR
Physical Separation (in core?) Gas Processing Unit through bubbling extraction Extract Kr, Xe, He and particles in suspension
Chemical Separation (by batch) Pyrochemical processing Unit
Located on-site, but outside the reactor vessel
Fission Products Extraction: Motivations Control physicochemical properties of the salt (control deposit, erosion and corrosion phenomena's) Keep good neutronic properties
Concept of MSFR: Fuel processing
14
Fuel processing mandatory to recover the produced fissile matter – Liquid fuel = reprocessing during reactor operation
4th Generation reactors => Breeder reactors
S. Delpech, E. Merle-Lucotte, D. Heuer, M. Allibert, V. Ghetta, C. Le-Brun, L. Mathieu, G. Picard, “Reactor physics and reprocessing scheme for innovative molten salt reactor system”, J. of Fluorine Chemistry, 130 Issue 1, p. 11-17 (2009)
Voir présentation de S. Delpech et J. Serp
Journées MSR de Massy, 2018 Présentation MSFR
ElementAbsorption
(per fission neutron)
Heavy Nuclei 0.9
Alkalines < 10-4
Metals 0.0014
Lanthanides 0.006
Total FPs 0.0075
Fast neutron spectrum very low capture cross-sections
Batch chemical processing:
On-line (bubbling) processing:
PhD thesis of Xavier DOLIGEZ
Concept of MSFR: Fuel processing
15
low impact of the processing (chemical and bubbling) on neutronics
Parallel studies of chemical and neutronic issues possible
Journées MSR de Massy, 2018 Présentation MSFR16
EVOL : Selection of the optimized fuel salt composition (deliverable 3.7)
Optimized initial composition of the fuel salt: LiF-ThF4-UF4-(TRU)F3 with (77.7-6.7-12.3-3.3 mol%) and U
enriched at 13%Density = 5085.6 - 0.8198*(T/K) - T(solid.) = 867 K
Neutronics, chemical and material behavior
very satisfying
MSFR started with EVOL selected fuel salt
TRU-started MSFR (neutro. benchmark)
Concept of MSFR: Starting modes and deployment capacities
Used for scenarios studies to close the
current fuel cycle and launch Gen4 MSRs
Voir présentation de D. Heuer
Journées MSR de Massy, 2018 Présentation MSFR17
Concept of MSFR: safety coefficients and inventories
Very good agreement between the different simulation tools – Large impact
of the nuclear database
-5
-4,5
-4
-3,5
-3
-2,5
-2
-1,5
-1
-0,5
0
0,05 0,5 5 50
Feed
back c
oeff
icie
nt
[pcm
/K]
Operation time [years]
233U-started MSFRPOLIMIDensityPOLIMIDopplerKI Density
KI Doppler
LPSC Density
LPSC Doppler
POLITODensityPOLITODopplerDensity TUDelft
Excellent (largely negative) feedback coefficients, the
simulation tool or the database used
Database: ENDF-B6
TRU-started MSFR
PhD thesis of Mariya Brovchenko
Journées MSR de Massy, 2018 Présentation MSFR
“Reference MSFR” neutronic characteristics: from EVOL to SAMOFAR
18
Review of previous studies list of constraints leading to the following proposal:
Parameter Value
Thermal/electric power 3000 MWth / ~1300 MWe
Fuel salt temperature rise in the core (°C) 100
Fuel molten salt - Initial compositionLiF-ThF4-
233UF4 or LiF-ThF4-enrUF4-(Pu-
MA)F3 with 77.5 mol% LiF
Fuel salt melting point (°C) 585
Mean fuel salt temperature (°C) 725
Fuel salt density (g/cm3) 4.1
Fuel salt dilation coefficient (g.cm-3/°C) 8.82 10-4
Fertile blanket salt - Initial composition
(mol%)LiF-ThF4 (77.5%-22.5%)
Breeding ratio (steady-state) 1.1
Total feedback coefficient (pcm/°C) -8
Toroidal core dimensions (m)Radius: 1.06 to 1.41
Height: 1.6 to 2.26
Fuel salt volume (m3) 18 (1/2 in the core)
Total fuel salt cycle in the fuel circuit 3.9 s
Intermediate fluidfluoroborate (8NaF-92NaBF4), FLiNaK, LiF-
ZrF4, FLiBe
Structural materials Ni-based alloy (Hastelloy-N)
Journées MSR de Massy, 2018 Présentation MSFR
SAMOFAR Project – Horizon2020
Safety Assessment of a MOlten salt FAst Reactor
5 technical work-packages:
WP1 Integral safety approach and system integration
WP2 Physical and chemical properties required for safety
analysis
WP3 Proof of concept of key safety features
WP4 Numerical assessment of accidents and transients
WP5 Safety evaluation of the chemical processes and plant
SAMOFAR will deliver the experimental proof of the following key safety features:
The freeze plug and draining of the fuel salt
New materials and new coatings to materials
Measurement of safety related data of the fuel salt
The dynamics of natural circulation of (internally heated) fuel salts
The reductive extraction processes to extract lanthanides and actinides from the fuel salt
4 years (2015-2019), 3,5 M€
Partners: TU-Delft (leader), CNRS, JRC-ITU, CIRTEN (POLIMI, POLITO), IRSN, AREVA,
CEA, EDF, KIT + PSI + CINVESTAV
Concept of Molten Salt Fast Reactor (MSFR)
19
Journées MSR de Massy, 2018 Présentation MSFR
Del.
n°Deliverable title
Lead
benef.
Delivery
date
D1.1Description of initial reference design and identification of
safety aspectsCNRS Month 6
D1.2 Identifying safety related physico-chemical and material data JRC Month 6
D1.3 Development of a power plant simulator CNRS Month 24
D1.4Safety issues of normal operation conditions, including start,
shut-down and load-followingCIRTEN Month 30
D1.5Development on an integral safety assessment methodology
for MSRIRSN Month 36
D1.6Identification of risks and phenomena involved,
identification of accident initiators and accident scenariosCIRTEN Month 36
D1.7
Improved Integral power plant design (reactor core and
chemical plant) to maximize safety and proposal for safety
demonstrator
CNRS Month 48
20
Concept of MSFR: SAMOFAR WP1 ”Integral safety approach and system integration”
Journées MSR de Massy, 2018 Présentation MSFR
Specificities of the MSFR impacting the safety analysis
• No control rods in the core Reactivity is controlled by the heat transfer rate in the HX + fuel salt feedback coefficients,
continuous fissile loading, and by the geometry of the fuel salt mass
No requirement for controlling the neutron flux shape (no DNB, uniform fuel irradiation, etc.)
• Fuel salt draining Emergency shutdown obtained by draining quickly the molten salt from the fuel circuit
Changing the fuel geometry allows for adequate shutdown margin and cooling
Fuel draining can be done passively or by operator action in 2 dedicated systems (normal operation and emergency draining systems)
• Liquid fuel Molten fuel salt acts as reactor fuel and coolant
Relative uniform fuel irradiation
A significant part of the fissile inventory is outside the active area where fissions occur (but in the core vessel)
Fuel reprocessing and loading during reactor operation
PhD theses of MariyaBrovchenko, Axel Laureau and
Delphine Gérardin
21
M. Brovchenko, D. Heuer, E. Merle-Lucotte, M. Allibert, V. Ghetta, A. Laureau, P. Rubiolo, “Design-related Studies for the Preliminary Safety Assessment of the Molten Salt Fast Reactor”, Nuclear Science and Engineering,175, 329–339 (2013)
Design definition (core and draining system at least)
Development of simulation tools dedicated (more generic)
Definition of the normal operation procedures
Safety evaluation: accident initiators? Accident scenarios?
Safety approach: severe accident? Barriers? Reactivity control?
Journées MSR de Massy, 2018 Présentation MSFR
Specificities of the MSFR impacting the safety analysis
• No control rods in the core Reactivity is controlled by the heat transfer rate in the HX + fuel salt feedback coefficients,
continuous fissile loading, and by the geometry of the fuel salt mass
No requirement for controlling the neutron flux shape (no DNB, uniform fuel irradiation, etc.)
• Fuel salt draining Emergency shutdown obtained by draining quickly the molten salt from the fuel circuit
Changing the fuel geometry allows for adequate shutdown margin and cooling
Fuel draining can be done passively or by operator action in 2 dedicated systems (normal operation and emergency draining systems)
• Liquid fuel Molten fuel salt acts as reactor fuel and coolant
Relative uniform fuel irradiation
A significant part of the fissile inventory is outside the active area where fissions occur (but in the core vessel)
Fuel reprocessing and loading during reactor operation
PhD theses of MariyaBrovchenko, Axel Laureau and
Delphine Gérardin
22
M. Brovchenko, D. Heuer, E. Merle-Lucotte, M. Allibert, V. Ghetta, A. Laureau, P. Rubiolo, “Design-related Studies for the Preliminary Safety Assessment of the Molten Salt Fast Reactor”, Nuclear Science and Engineering,175, 329–339 (2013)
Design definition (core and draining system at least)
Development of simulation tools dedicated (more generic)
Definition of the normal operation procedures
Safety evaluation: accident initiators? Accident scenarios?
Safety approach: severe accident? Barriers? Reactivity control?
Journées MSR de Massy, 2018 Présentation MSFR
Design aspects impacting the MSFR safety analysis
LOLF accident (Loss of Liquid Fuel) → no tools available for quantitative analysis but qualitatively:
• Fuel circuit: complex structure, multiple connections
• Potential leakage: collectors connected to draining tank
→ Proposition of an ‘Integrated MSFR design’ to suppress pipes/leakage
Journées MSR de Massy, 2018 Présentation MSFR
Specificities of the MSFR impacting the safety analysis
• No control rods in the core Reactivity is controlled by the heat transfer rate in the HX + fuel salt feedback coefficients,
continuous fissile loading, and by the geometry of the fuel salt mass
No requirement for controlling the neutron flux shape (no DNB, uniform fuel irradiation, etc.)
• Fuel salt draining Emergency shutdown obtained by draining quickly the molten salt from the fuel circuit
Changing the fuel geometry allows for adequate shutdown margin and cooling
Fuel draining can be done passively or by operator action in 2 dedicated systems (normal operation and emergency draining systems)
• Liquid fuel Molten fuel salt acts as reactor fuel and coolant
Relative uniform fuel irradiation
A significant part of the fissile inventory is outside the active area where fissions occur (but in the core vessel)
Fuel reprocessing and loading during reactor operation
PhD theses of MariyaBrovchenko, Axel Laureau and
Delphine Gérardin
24
M. Brovchenko, D. Heuer, E. Merle-Lucotte, M. Allibert, V. Ghetta, A. Laureau, P. Rubiolo, “Design-related Studies for the Preliminary Safety Assessment of the Molten Salt Fast Reactor”, Nuclear Science and Engineering,175, 329–339 (2013)
Design definition (core and draining system at least)
Development of simulation tools dedicated (more generic)
Definition of the normal operation procedures
Safety evaluation: accident initiators? Accident scenarios?
Safety approach: severe accident? Barriers? Reactivity control?
Voir présentation de A. Laureau
Journées MSR de Massy, 2018 Présentation MSFR
Specificities of the MSFR impacting the safety analysis
• No control rods in the core Reactivity is controlled by the heat transfer rate in the HX + fuel salt feedback coefficients,
continuous fissile loading, and by the geometry of the fuel salt mass
No requirement for controlling the neutron flux shape (no DNB, uniform fuel irradiation, etc.)
• Fuel salt draining Emergency shutdown obtained by draining quickly the molten salt from the fuel circuit
Changing the fuel geometry allows for adequate shutdown margin and cooling
Fuel draining can be done passively or by operator action in 2 dedicated systems (normal operation and emergency draining systems)
• Liquid fuel Molten fuel salt acts as reactor fuel and coolant
Relative uniform fuel irradiation
A significant part of the fissile inventory is outside the active area where fissions occur (but in the core vessel)
Fuel reprocessing and loading during reactor operation
PhD theses of MariyaBrovchenko, Axel Laureau and
Delphine Gérardin
25
M. Brovchenko, D. Heuer, E. Merle-Lucotte, M. Allibert, V. Ghetta, A. Laureau, P. Rubiolo, “Design-related Studies for the Preliminary Safety Assessment of the Molten Salt Fast Reactor”, Nuclear Science and Engineering,175, 329–339 (2013)
Design definition (core and draining system at least)
Development of simulation tools dedicated (more generic)
Definition of the normal operation procedures
Safety evaluation: accident initiators? Accident scenarios?
Safety approach: severe accident? Barriers? Reactivity control?
Voir présentation de S. Beils et D. Gérardin
Journées MSR de Massy, 2018 Présentation MSFR
Sizing of the facilities:
Small size: ~1liter - chemistry and corrosion – off-line processingPyrochemistry: basic chemical data, processing, monitoring
Medium size: ~100 liters – hydrodynamics, noble FP extraction, heat exchangesProcess analysis, modeling, technology tests
Full size experiment: ~1 m3 salt / loop – validation at loop scaleValidation of technology integration and hydrodynamics models
3 levels of radio protection:
Inactive simulant salt Standard laboratoryHydrodynamics, material, measurements, model validation
Low activity level (Th, depleted U) Standard lab + radio protectPyrochemistry, corrosion, chemical monitoring
High activity level (enrichedU, 233U, Pu, MA) Nuclear facilityFuel salt processing: Pyrochemistry, , Actinides recycling
Demonstration steps and Demonstrator of MSFR
26
Journées MSR de Massy, 2018 Présentation MSFR
Some PhD Thesis in France on MSR
Gabriela DURAN, "Étude du comportement de l'uranium et de l'iode dans le mélange de fluorures fondus LiF-ThF4 à 650°C", PhD Thesis, Université Paris Saclay, France (2017)
Axel LAUREAU, "Développement de modèles neutroniques pour le couplage thermohydraulique du MSFR et le calcul de paramètres cinétiques effectifs", PhD Thesis, Grenoble Alpes University, France (2015)
Davide RODRIGUES, "Solvatation du thorium par les fluorures en milieu sel fondu à haute température : application au procédé d'extraction réductrice pour le concept MSFR", PhD Thesis, Paris Sud University (2015)
Mariya BROVCHENKO, "Etudes préliminaires de sûreté du réacteur à sels fondus MSFR", PhD Thesis, Grenoble Institute of Technology, France (2013)
Xavier DOLIGEZ, “Influence du retraitement physico-chimique du sel combustible sur le comportement du MSFR et sur le dimensionnement de son unité de retraitement”, PhD Thesis, Grenoble Institute of Technology and EDF, France (2010)
Elsa MERLE-LUCOTTE, “Le cycle Thorium en réacteurs à sels fondus peut-il être une solution au problème énergétique du XXIème siècle ? Le concept de TMSR-NM”, Habilitation à Diriger les Recherches, Grenoble INP, France (2008)
Ludovic MATHIEU, “Cycle Thorium et Réacteurs à Sel Fondu: Exploration du champ des Paramètres et des Contraintes définissant le Thorium Molten Salt Reactor”, PhD Thesis, Grenoble Institute of Technology and EDF, France (2005)
Jorgen FINNE, “Chimie des mélanges de sels fondus - Application à l'extraction réductrice d'actinides et de lanthanides par un métal liquide”, PhD Thesis, EDF-CEA-ENSCP, Paris, France (2005)
Fabien PERDU, “Contributions aux études de sûreté pour des filières innovantes de réacteurs nucléaires”, PhD Thesis, Grenoble Institute of Technology, France (2003)
Alexis NUTTIN, “Potentialités du concept de réacteur à sels fondus pour une production durable d’énergie nucléaire basée sur le cycle thorium en spectre épithermique”, PhD Thesis, Grenoble I University and EDF, France (2002)
David LECARPENTIER, “Le concept AMSTER, aspects physiques et sûreté”, EDF and CNAM, Paris, France (2001)
Available on http://lpsc.in2p3.fr/index.php/fr/38-activites-scientifiques/physique-des-reacteurs-
nucleaires/183-msfr-bibliographie or ‘MSFR LPSC’ in google search
Journées MSR de Massy, 2018 Présentation MSFR28
Some documents mentioning the MSRF
MSR-Safety White Paper, Gen4 International Forum, SSC-MSR, under review (2017)
M. Allibert, M. Aufiero, M. Brovchenko, S. Delpech, V. Ghetta, D. Heuer, A. Laureau, E. Merle-Lucotte, "Chapter 7 - Molten Salt Fast Reactors", Handbook of Generation IV Nuclear Reactors, WoodheadPublishing Series in Energy (2015)
“Introduction of Thorium in the Nuclear Fuel Cycle”, Nuclear Science 2015, NEA website https://www.oecd-nea.org/science/pubs/2015/7224-thorium.pdf (2015)
J. Serp, M. Allibert, O. Beneš, S. Delpech, O. Feynberg, V. Ghetta, D. Heuer, D. Holcomb, V. Ignatiev, J.L. Kloosterman, L. Luzzi, E. Merle-Lucotte, J. Uhlíř, R. Yoshioka, D. Zhimin, “The molten salt reactor (MSR) in generation IV: Overview and Perspectives”, Prog. Nucl. Energy, 1-12 (2014)
H. Boussier, S. Delpech, V. Ghetta, D. Heuer, D.E. Holcomb, V. Ignatiev, E. Merle-Lucotte, J. Serp, “The Molten Salt Reactor in Generation IV: Overview and Perspectives”, Proceedings of the Generation4 International Forum Symposium, San Diego, USA (2012)
CEA, Rapport sur la gestion durable des matières nucléaires - Tome 4 : Les autres filières à neutrons rapides de 4ème génération (2012)
C. Renault, S. Delpech, E. Merle-Lucotte, R. Konings, M. Hron, V. Ignatiev, "The molten salt reactor: R&D status and perspectives in Europe", Poceedings of FISA2009: 7th European Commission conference on EURATOM research and training in reactor systems, Prague, Tchéquie (2009)
See also the annex on Molten Salt Reactor Systems of the Strategic Research Agenda (published in January 2012)
Agenda of the SNETP (Sustainable Nuclear Energy Technology Platform of Europe) here: http://www.snetp.eu/www/snetp/.../sra_annex-MSRS.pdf
Journées MSR de Massy, 2018 Présentation MSFR29 [email protected]
Journées MSR de Massy, 2018 Présentation MSFR30
Liquid-fueled reactors: fluoride or chloride? Chemistry
Chemical characteristics
Chloride salts less studied that fluoride salts for nuclear applications
Chloride salts: some have a lower melting temperature (50/100K) and larger actinides solubilities
Chloride salts do not dissolve oxides
Chloride salts are more difficult to dehydrate → more H2O contamination and thus more corrosion risk
More processes of separative chemistry for chloride salts
Journées MSR de Massy, 2018 Présentation MSFR31
Parameter Fluoride Salt Chloride Salt
Thorium capture cross-section in core (barn) 0.61 0.315
Thorium amount in core (kg) 42 340 47 160
Thorium capture rate in core (mole/day) 11.03 8.48
Thorium capture cross-section in blanket (barn) 0.91 0.48
Thorium amount in the blanket (kg) 25 930 36 400
Thorium capture rate in the blanket (mole/day) 1.37 2.86233U initial inventory (kg) 5720 6867
Neutrons per fission in core 2.50 2.51233U capture cross-section in core (barn) 0.495 0.273233U fission cross-section in core (barn) 4.17 2.76
Capture/fission ratio (spectrum-dependent) 0.119 0.099
Total breeding ratio 1.126 1.040
232Th Capture cross-section
Liquid-fueled reactors: fluoride or chloride? Breeding
Journées MSR de Massy, 2018 Présentation MSFR
Historical studies of MSR: Oak Ridge Nat. Lab. - USA
1964 – 1969: Molten Salt Reactor Experiment (MSRE)Experimental ReactorPower: 7.4 MWthTemperature: 650°CU enriched 30% (1966 - 1968)
233U (1968 – 1969) - 239Pu (1969)No Thorium inside
1970 - 1976: Molten Salt Breeder Reactor (MSBR)Never built
Power: 2500 MWth Thermal neutron spectrum
1954 : Aircraft Reactor Experiment (ARE)Operated during 1000 hours Power = 2.5 MWth
Molten Salt Reactors – Historical Studies
32
Journées MSR de Massy, 2018 Présentation MSFR
Molten Salt Reactor (MSR)Renewal of the concept
• Thorims-NES5 then FUJI-AMSB in Japan since the 80’sReactor of very low specific power fed with 233U produced in sub-critical reactors
• Resumption of the MSBR’s studies by CEA and EDF – 70’s to 80’s
Molten Salt Reactors - Renewal of the concept
33
Journées MSR de Massy, 2018 Présentation MSFR
Past studies on Molten Salt Reactors at EDF R&D
since 2000
Contact person: David LECARPENTIER, EDF R&D
Molten Salt Reactors - Renewal of the concept
At the begining of the 2000’ 1. Study of actinide Burner on thorium support AMSTER (adaptation
of the MSBR) – 2001
From 2001 to 2005 Thorium breeder in thermal spectrum considered as a better option for sustainalitity.
1. In-house research : neutronic / processing / corrosion2. Support to CNRS and CEA research3. Contribution to European projects
MOST (2001), ALISIA (2007), SAMOFAR (2015)
Since 2005 non moderated Thorium breeder as most promizing option for sustainability
Journées MSR de Massy, 2018 Présentation MSFR
• Thorims-NES5 then FUJI-AMSB in Japan since the 80’sReactor of very low specific power fed with 233U produced in sub-critical reactors
• Resumption of the MSBR’s studies by CEA and EDF since the 90’s
• TIER-1 project of C. Bowman in the 90’sPu burner (LWR’s spent fuel assemblies dissolved in liquid fuel) in sub-critical reactors
• TASSE (CEA) project in the 90’sPlutonium burner (liquid fuel) in sub-critical reactors
• AMSTER (EDF) project in the 90’sPlutonium burner then breeder reactor in Thorium cycle
• REBUS (EDF), MOSART (Kurchakov Institute), SPHINX (Czech Republic)Projects of actinide burners
• MOST Network, FP5, 2001-2004European network having assessed the studies, the experiments and the state of knowledge
concerning molten salt reactors
• ALISIA (Assessment of Liquid Salts for Innovative Applications), FP6, 2007-2008European Action - Lead authors : O.Bene C. Cabet, S. Delpech, P. Hosnedl, V. Ignatiev, R. Konings,
D. Lecarpentier, O. Matal, E. Merle-Lucotte, C. Renault, J. Uhlir, 6st Euratom Framework Prog.
Molten Salt Reactors - Renewal of the concept
35
Journées MSR de Massy, 2018 Présentation MSFR
• Participation to the project TIER I of C. Bowman (1998)
• Re-evaluation of the MSBR from 1999 to 2002
Use of a probabilistic neutronic code (MCNP)
Development of an in-house evolution code for materials (REM)
Coupling of the neutronic code with the evolution code
• From the Thorium Molten Salt Reactor to the Molten Salt Fast Reactor
Breeder in the Thorium fuel cycle and Actinide Burner Reactor
Developed to solve the problems of the MSBR project– Bad (null to positive) feedback coefficients
– Positive void coefficient
– Unrealistic reprocessing
– Problems specific to the graphite moderator
- Lifespan
- Reprocessing and storage
- Fire risk
PhD thesis of Alexis NUTTIN
MSR - Renewal of the concept – CNRS studies
36
Journées MSR de Massy, 2018 Présentation MSFR37
Total feedback coefficient:Ok if <0 at least
Influence studied through 4 core characteristics:
- Total feedback coefficient
Historical MSR Studies at CNRSInfluence of the neutron spectrum on the core behavior
Journées MSR de Massy, 2018 Présentation MSFR38
Historical MSR Studies at CNRSInfluence of the neutron spectrum on the core behavior
232Th/233U cycle: neutron balance better in thermal or fast spectrum
neutron captures in moderator in thermal spectrum
Influence studied through 4 core characteristics:
- Total feedback coefficient
- Breeding ratio:
+
Journées MSR de Massy, 2018 Présentation MSFR39
Historical MSR Studies at CNRSInfluence of the neutron spectrum on the core behavior
1graphiteL
no graphite
moderator+
Influence studied through 4 core characteristics:
- Total feedback coefficient
- Breeding ratio
- Neutron flux / Graphite lifespan
Journées MSR de Massy, 2018 Présentation MSFR40
Historical MSR Studies at CNRSInfluence of the neutron spectrum on the core behavior
Three types of configuration:
- thermal (r = 3-6 cm)
- epithermal (r = 6-10 cm)
- fast (r > 10 cm)
Journées MSR de Massy, 2018 Présentation MSFR41
Initial fissile inventory of 3 to 4.5 tons / GWe reachable
MSFR: Design and Fissile Inventory Optimization
Burning efficiency
Breeding and deployment capacities
Small fuel salt volumes favoured: > 90% of TRUs burned after only 25 years of operation,
and ~ 96% after 50 years of operation
Deployment capacities: favors the medium volumes (10 m3 to 20 m3)
Journées MSR de Massy, 2018 Présentation MSFR
R&D Activities in Reactor Physics, Design and Safety at CNRS
Concepts considered:
• Large scale MSFR: called “reference MSFR” and studied since around 10 years first at CNRS and now in European and national programs –Objective: defining a large power reactor to identify the challenges of such a concept + define the acceptable configurations
• Small-size MSFR: called “S-MSFR” and studies foreseen in the coming years – Objective: see how to simplify the MSFR concept + define the steps and a R&D roadmap up to industrialization of such a reactor
R&D Common thematics
• Neutronics and reactor physics studies based on multiphysics (code ref = TFM-OpenFOAM coupling code) and evolutive Monte-Carlo calculations + a system code (basic principle simulator) under development
• Safety analysis and evaluations using classical safety tools (FFMEA, MLD, LoD) + Resistance to proliferation preliminary analysis
• Experimental studies of the salt operation, the salt control and processing
Journées MSR de Massy, 2018 Présentation MSFR
R&D Activities in Reactor Physics, Design and Safety at CNRS
Concepts considered:
• Large scale MSFR: called “reference MSFR” and studied since around 10 years first at CNRS and now in European and national programs –Objective: defining a large power reactor to identify the challenges of such a concept + define the acceptable configurations
• Small-size MSFR: called “S-MSFR” and studies foreseen in the coming years – Objective: see how to simplify the MSFR concept + define the steps and a R&D roadmap up to industrialization of such a reactor
R&D progress
• Studies at a preliminary stage
• Initial fuel composition, preliminary design
Perspectives and research frame
• Frame : NEEDS French interdisciplinary program, collaboration with AREVA, other collaborations?
• Perspectives: PhD thesis started in October 2017, realistic SMR design + fuel cycle assessment + transient calculations and safety analysis
Journées MSR de Massy, 2018 Présentation MSFR
Small Modular Reactor – S-MSFR
Power 100 MW to 300 MW
Mean fuel salt
temperature675 °C
Fuel temperature increase
in the core30 °C
Initial fuel salt
composition
75% LiF-(Heavy Nuclei)F4 –
in Th/233U and U/Pu fuel cycle
Core sizeInternal diameter ~1.3 m
External diameter ~2.3 m
Fuel salt volume
2 to 4 m3
1.1 to 2.3 in core
0.9 to 1.7 in external circuit
Total fuel cycle in the fuel
circuit3 - 5 s
Objectives: ease the constructability while reducing the costs
Idea: operation during around 30 years with the same fuel salt without chemical processing with a simplified concept (heat exchangers simplified, classical nuclear
materials, no fertile blanket nor draining tank, …)
PhD thesis of Johann Martinet
Journées MSR de Massy, 2018 Présentation MSFR
No radial blanket
and H/D=1
No radial blanket
and H/D=1
Power [MWth] 100 200
Initial 233U load [kg] 654 654
Fuel reprocessing of 1l/day
Feeding in 233U [kg/an] 11.38 23.38
Breeding ratio -29.83% -30.64%
Total 233U needed [kg] 1013.87 1388.37
Fuel reprocessing of 4l/day
Feeding in 233U [kg/an] 11.20 22.58
Breeding ratio -29.37% -29.59%
Total 233U needed [kg] 1001.86 1353.13
Around 650kg of 233U to start
Under-breeder reactor
Low impact of the chemical reprocessing rate
(not mandatory for the demonstrator / SMR)
Small Modular Reactor – S-MSFRPreliminary studies of the fissile inventory and breeding capacities in the Th fuel cycle
Journées MSR de Massy, 2018 Présentation MSFR
No radial blanket
and H/D=1
No radial blanket
and H/D=1
Radial blanket
and H/D=1
Radial blanket
and H/D=1
Power [MWth] 100 200 100 200
Initial 233U load [kg] 654 654 667 667
Fuel reprocessing of 1l/day
Feeding in 233U [kg/an] 11.38 23.38 1.72 4.70
Breeding ratio -29.83% -30.64% -4.52% -6.16%
Total 233U needed [kg] 1013.87 1388.37 738.83 835.16
Breeding ratio (radial + axial fertile blankets)
1.81% -0.04%
Fuel reprocessing of 4l/day
Feeding in 233U [kg/an] 11.20 22.58 1. 48 3.58
Breeding ratio -29.37% -29.59% -3.88% -4.69%
Total 233U needed [kg] 1001.86 1353.13 722.50 794.21
Breeding ratio (radial + axial fertile blankets)
2.49% 1.54%
Addition of axial + radial fertile blankets small modular breeder MSFR
Small Modular Reactor – S-MSFRPreliminary studies of the fissile inventory and breeding capacities in the Th fuel cycle
Journées MSR de Massy, 2018 Présentation MSFR
Small Modular Reactor – S-MSFRPreliminary studies of the fissile inventory and breeding capacities in the Th fuel cycle
Journées MSR de Massy, 2018 Présentation MSFR
enrichedU mixed with transuranic elements possible with U enrichment of 15% - 20%
48
Small Modular Reactor – S-MSFRPreliminary studies of the fissile inventory and breeding capacities in the Th fuel cycle
Journées MSR de Massy, 2018 Présentation MSFR
enrichedU mixed with transuranic elements possible with U enrichment of 15% - 20%
Uranium enriched at 20% mixed with irradiated MOx-Th with a ratio of Th/(Th+U) = 20 to 65%
49
Small Modular Reactor – S-MSFRPreliminary studies of the fissile inventory and breeding capacities in the Th fuel cycle
Journées MSR de Massy, 2018 Présentation MSFR
Small Modular Reactor – S-MSFR
Power 100 MW to 300 MW
Mean fuel salt
temperature675 °C
Fuel temperature increase
in the core30 °C
Initial fuel salt
composition
75% LiF-(Heavy Nuclei)F4 –
in Th/233U and U/Pu fuel cycle
Core sizeInternal diameter ~1.3 m
External diameter ~2.3 m
Fuel salt volume
2 to 4 m3
1.1 to 2.3 in core
0.9 to 1.7 in external circuit
Total fuel cycle in the fuel
circuit3 - 5 s
Objectives: ease the constructability while reducing the costs
Idea: operation during around 30 years with the same fuel salt without chemical processing with a simplified concept (heat exchangers simplified, classical nuclear
materials, residual heat, no fertile blanket nor draining tank, …)
PhD thesis of Johann Martinet
Journées MSR de Massy, 2018 Présentation MSFR
R&D Activities in Reactor Physics, Design and Safety at CNRS
Concepts considered:
• Large scale MSFR: called “reference MSFR” and studied since around 10 years first at CNRS and now in European and national programs –Objective: defining a large power reactor to identify the challenges of such a concept + define the acceptable configurations
• Small-size MSFR: called “S-MSFR” and studies foreseen in the coming years – Objective: see how to simplify the MSFR concept + define the steps and a R&D roadmap up to industrialization of such a reactor
R&D progress• Advanced studies (reactor physics, design, safety, chemistry, components…)
including experimental facilities (2 loops under operation)
• See EVOL and SAMOFAR results
Perspectives and research frame
• Frame: SAMOFAR European Project and national projects (France, Switzerland)
• Perspectives: new European project (advanced simulations for safety), complete the safety study including all systems/components, define the instrumentation, control and inspection, demonstration steps, definition of the demonstrator
Journées MSR de Massy, 2018 Présentation MSFR52
Tools for the Simulation of Reactor Evolution:Evolving Monte-Carlo calculations
Coupling of the in-house code REM for materials
evolution with the probabilistic code MCNP for
neutronic calculations
Journées MSR de Massy, 2018 Présentation MSFR53
Tools for the Simulation of Reactor Evolution:Evolving Monte-Carlo calculations
Bateman Equation for nucleus i (in the whole system):
BC
Bi
CBChem
Bii
ij
Bii
BC
Ci
BCChem
Bjijjij
Bi NNNNNXt
N
‘B’ = location of nucleus i in the sub-system B ‘B → C’ = transfer from sub-system B to sub-system C
Calculation of the evolution of matter in each part of the system
Determination of isotopes concentrations, gamma or neutron flux + the residual heat (fundamental data for radioprotection) everywhere (core, reprocessing unit,
bubbling system, draining tanks…) – Basis of the design and of the safety and radioprotection assessment of the whole system
with
PhD thesis of Xavier DOLIGEZ
production by nuclear reaction
production by radioactive decay
disappearance by nuclear reaction
disappearance by radioactive decay
Journées MSR de Massy, 2018 Présentation MSFR
Neutronic irradiation damages to the structural materials (modify their physicochemical properties) = displacements per atom, production of Helium gas, transmutation of Tungsten
in Osmium, activation – At high temperatures
Ni W Cr Mo Fe Ti C Mn Si Al B P S
79.432 9.976 8.014 0.736 0.632 0.295 0.294 0.257 0.252 0.052 0.033 0.023 0.004
Tmax=680°C
Reflector
Concept of MSFR: choice of the structural materials (Ni-based alloys)
54
Example of material proposed in the EVOL project (with Tungsten):
Journées MSR de Massy, 2018 Présentation MSFR
He accumulation (ppm) on the most irradiatedpart of the reflectors with Ni-based alloys
(no He diffusion)
dpa in the structural materials(depth & distance from core
axis)
Radiation damages concentrated on the core axis and concern a limited material depth
orthocylinder
Displacement per Atom (dpa)
Concept of MSFR: irradiation damages
Journées MSR de Massy, 2018 Présentation MSFR
Main contribution to Helium production in the most irradiated area (radius 20 cm /thickness 2 cm) for a fuel salt volume of 18 m3 due to 58Ni
Helium production in the structural materials
Ni W Cr Mo Fe Ti C Mn Si Al B P S
79.432 9.976 8.014 0.736 0.632 0.295 0.294 0.257 0.252 0.052 0.033 0.023 0.004
Regular replacements of these area to be planned (first 10cm only) or addition of another
material to protect the surface of these reflectors?
Fuel salt volume 18 m3
Concept of MSFR: irradiation damages
Journées MSR de Massy, 2018 Présentation MSFR
Transmutation of the Tungsten contained in the alloy into Rhenium and Osmium
Ni W Cr Mo Fe Ti C Mn Si Al B P S
79.432 9.976 8.014 0.736 0.632 0.295 0.294 0.257 0.252 0.052 0.033 0.023 0.004
Transmutation Cycle of W in Re and Os (neutronic captures + decays):
W, Re and Os contents of the most irradiated area for a fuel salt volume of 18m3:
• Value of the acceptable limit?
• Impact on the structural materials resistance?
→ Alloy without Tungsten
Fuel salt volume 18 m3
Concept of MSFR: irradiation damages
Journées MSR de Massy, 2018 Présentation MSFR
Structural elements: layers
Displacements per atom He production Tungsten
transmutation
0-2.5 cm 6.8 dpa/year 12 ppm / year 0.11 at% /year
2.5-7.5 cm 3.5 dpa/year 6 ppm / year 0.07 at% /year
To be experimentally studied: He production (maximal acceptable amount, diffusion effects?) + Effects on the long-term resistance of structural materials due to W
transmutation + Effects of high temperature on structural materials
Neutronic irradiation damages to the structural materials (modify their physicochemical properties) = displacements per atom, production of Helium gas,
transmutation of Tungsten in Osmium, activation
Conclusions: - Irradiation damages low + Limits unknown- Irradiation damages limited to the first 10 cm (replaced 3-4 times or
use a thin layer of SiC for example as thermal protection)- Materials not under large mechanical stress
Ni W Cr Mo Fe Ti C Mn Si Al B P S
79.432 9.976 8.014 0.736 0.632 0.295 0.294 0.257 0.252 0.052 0.033 0.023 0.004
Concept of MSFR: irradiation damages
58